Apparatus and method to visually indicate the status of a data storage device

ABSTRACT

A data storage and retrieval system that comprises a data storage device is disclosed. The data storage and retrieval system further comprises a first LED, a second LED, a third LED, and a fourth LED, interconnected with the data storage device. The data storage device causes the first LED and the second LED to emit first light comprising a first color if the data storage device detects an internal failure. Alternatively, the storage device causes the third LED and the fourth LED to emit second light comprising a second color if the data storage device remains operative.

FIELD OF THE INVENTION

This invention relates to an apparatus and method to visually indicatethe status of a data storage device.

BACKGROUND OF THE INVENTION

Data storage and retrieval systems are used to store informationprovided by one or more host computer systems. Such data storage andretrieval systems receive requests to write information to one or moredata storage devices, and requests to retrieve information from thoseone or more data storage devices. Upon receipt of a write request, thesystem stores information received from a host computer in a data cache.In certain implementations, a copy of that information is also stored ina nonvolatile storage device. Upon receipt of a read request, the systemrecalls information from the one or more data storage devices and movesthat information to the data cache. Thus, the system is continuouslymoving information to and from a plurality of data storage devices, andto and from the data cache.

Certain standards applicable to the interconnection of the plurality ofdata storage devices to the data storage and retrieval system requirethat two LEDs be interconnected with each data storage device, where oneLED visually indicates whether the interconnected data storage device isoperable, and another LED visually indicates whether the interconnecteddata storage device is in use. Thus, a data storage and retrieval systemcomprising (X) data storage devices, and compliant with the Standardcomprises (2×) LEDs. The failure of any one of those (2×) LEDs, however,may require that, in order to remain compliant with the standard, one ormore data storage devices be taken out of service to repair or replacethat failed LED.

What is needed is an apparatus that complies with the interconnectionstandard, but that does not require that one or more data storagedevices be taken out of service in the event a single LED fails.

SUMMARY OF THE INVENTION

Applicants' invention comprises a data storage and retrieval system thatcomprises a data storage device. The data storage and retrieval systemfurther comprises a first LED interconnected with the data storagedevice, a second LED is interconnected with the data storage device, andwhere the first LED and the second LED are capable of emitting firstlight comprising a first color.

The data storage and retrieval system further comprises a third LEDinterconnected with the data storage device and a fourth LEDinterconnected with the data storage device, and where the third LED andthe fourth LED are capable of emitting second light comprising a secondcolor.

The data storage device causes the first LED and the second LED to emitthe first light if the data storage device detects an internal failure.Alternatively, the storage device causes the third LED and the fourthLED to emit the second light if the data storage device is operative.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from a reading of the followingdetailed description taken in conjunction with the drawings in whichlike reference designators are used to designate like elements, and inwhich:

FIG. 1 is a block diagram showing a first embodiment of Applicants' datastorage and retrieval system;

FIG. 2 is a block diagram showing one embodiment of Applicants'backplane comprising a plurality of SCA receptacles, where thatbackplane is disposed in the system of FIG. 1;

FIG. 3 is a block diagram showing one embodiment of Applicants' SCAconnector;

FIG. 4, which includes FIG. 4A and 4B, is a block diagram showing asecond embodiment of Applicants' SCA connector;

FIG. 5, which includes FIG. 5A and FIG. 5B, is a block diagram showing(N) data storage devices interconnected with the backplane of FIG. 1using (N) SCA connectors and (4N) LEDs disposed on Applicants'backplane;

FIG. 6A is a block diagram showing a light pipe attached to thelight-emmiting surfaces of two LEDs;

FIG. 6B, which includes FIGS. 6B and FIG. 6C, is a block diagram showing(2N) light pipes attached to the (4N) LEDs of FIG. 5;

FIG. 7 is a block diagram showing an enclosure housing the assembly ofFIG. 6;

FIG. 8 is a block diagram showing a first embodiment of the electricalinterconnections between a data storage device and one pair of LEDsdisposed on Applicants' backplane;

FIG. 9 is a block diagram showing a second embodiment of the electricalinterconnections between a data storage device and one pair of LEDsdisposed on Applicants' backplane;

FIG. 10 is a block diagram showing a third embodiment of the electricalinterconnections between a data storage device and one pair of LEDsdisposed on Applicants' backplane;

FIG. 11 is a perspective view of a lens assembly disposed on the distalends of the light pipes of FIG. 6;

FIG. 12, which includes FIG.12A and 12B, is a flow chart summarizingadditional steps of Applicants' method;

FIG. 13 is a flow chart summarizing additional steps of a firstembodiment of Applicant's method; and

FIG. 14 is a flow chart summarizing additional steps of a secondembodiment of Applicants' method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention is described in preferred embodiments in the followingdescription with reference to the Figures, in which like numbersrepresent the same or similar elements. The invention will be describedas embodied in an information storage and retrieval system whichincludes two clusters, a plurality of host adapter ports, a plurality ofdevice adapter ports, and a data cache. The following description ofApplicant's apparatus to visually indicate the status of, and thecurrent operation of, one or more data storage devices is not meant,however, to limit Applicant's invention to data processing applications,as the invention herein can be applied to information storage ingeneral.

Referring now to FIG. 1, information storage and retrieval system 100 iscapable of communication with host computer 390 via communication link395. The illustrated embodiment of FIG. 1 shows a single host computer.In other embodiments, Applicants' information storage and retrievalsystem is capable of communicating with a plurality of host computers.

Host computer 390 comprises a computer system, such as a mainframe,personal computer, workstation, and combinations thereof, including anoperating system such as Windows, AIX, Unix, MVS, LINUX, etc. (Windowsis a registered trademark of Microsoft Corporation; AIX is a registeredtrademark and MVS is a trademark of IBM Corporation; and UNIX is aregistered trademark in the United States and other countries licensedexclusively through The Open Group.) In certain embodiments, hostcomputer 390 further includes a storage management program. The storagemanagement program in the host computer 390 may include thefunctionality of storage management type programs known in the art thatmanage the transfer of data to a data storage and retrieval system, suchas the IBM DFSMS implemented in the IBM MVS operating system.

In certain embodiments, Applicants' information storage and retrievalsystem 100 includes a first plurality of host adapter ports 101 A whichincludes adapter ports 102-105 and 107-110; and a second plurality ofhost adapter ports 101 B which includes adapter ports 112-115 and117-120. In other embodiments, Applicants' information storage andretrieval system includes fewer than 16 host adapter ports. In otherembodiments, Applicants' information storage and retrieval systemcomprises more than 16 host adapter ports. Regardless of the number ofhost adapter ports disposed in any embodiments of Applicants' system,each of those host adapter ports comprises a shared resource that hasequal access to both central processing/cache elements 130 and 140.

Each host adapter may comprise one or more Fibre Channel ports, one ormore FICON ports, one or more ESCON ports, or one or more SCSI ports.Each host adapter is connected to both clusters through interconnect bus121 such that each cluster can handle I/O from any host adapter.Internal buses in each subsystem are connected via a Remote I/O bridge155/195 between the processor portions 130/140 and I/O portions 160/170,respectively.

Processor portion 130 includes processor 132 and cache 134. In certainembodiments, processor portion 130 further includes memory 133. Incertain embodiments, memory device 133 comprises random access memory.In certain embodiments, memory device 133 comprises non-volatile memory.

Processor portion 140 includes processor 142 and cache 144. In certainembodiments, processor portion 140 further includes memory 143. Incertain embodiments, memory device 143 comprises random access memory.In certain embodiments, memory device 143 comprises non-volatile memory.

I/O portion 160 comprises a plurality of device adapter ports 161 whichin the illustrated embodiment of FIG. 1 comprises device adapter ports165, 166, 167, and 168. I/O portion 160 further comprise nonvolatilestorage (“NVS”) 162 and battery backup 164 for NVS 162.

I/O portion 170 comprises a plurality of device adapter ports 171 whichin the illustrated embodiment of FIG. 1 comprises device adapter ports175, 176, 177, and 178. I/O portion 170 further comprise nonvolatilestorage (“NVS”) 172 and battery backup 174 for NVS 172.

In certain embodiments of Applicants' system, one or more host adapterports 101, processor portion 130, and one or more device adapter ports161, are disposed in a controller disposed in Applicants' informationstorage and retrieval system. Similarly, in certain embodiments, one ormore host adapter ports 111, processor portion 160, and one or moredevice adapter ports 171, are disposed in a second controller disposedin Applicants' information storage and retrieval system. In theseembodiments, Applicants' system 100 includes two controllersinterconnected to a plurality of data storage devices.

In the illustrated embodiment of FIG. 1, sixteen data storage devicesare organized into two arrays, namely array 180 and array 190. Theillustrated embodiment of FIG. 1 shows two storage device arrays. Eachstorage array appears to a host computer as one or more logical devices.

In certain embodiments, one or more of the data storage devices comprisea plurality of hard disk drive units. In certain embodiments, arrays 180and 190 utilize a RAID protocol. In certain embodiments, arrays 180 and190 comprise what is sometimes called a JBOD array, i.e. “Just a BunchOf Disks,” where those arrays are not configured according to RAID. Instill other embodiments, arrays 180 and 190 comprise what is sometimescalled a SBOD array, i.e. “Switched Bunch Of Disks,” where those arraysare not configured according to RAID.

The illustrated embodiment of FIG. 1 shows two storage device arrays. Inother embodiments, Applicants' system includes a single storage devicearray. In yet other embodiments, Applicants' system includes more thantwo storage device arrays.

In certain embodiments, one or more data storage devices, such as forexample plurality of data storage devices 180 and/or plurality of datastorage devices 190, are interconnected with Applicants' informationstorage and retrieval system through a backplane assembly. In certainembodiments, that backplane comprises a plurality of Single ConnectorAttachment (“SCA”) backplane receptacles such that each data storagedevice is interconnected with the backplane by an SCA connector matedwith an SCA backplane receptacle. In certain embodiments, that backplanecomprises a plurality of S-ATA backplane receptacles such that each datastorage device is interconnected with the backplane by an S-ATAconnector mated with an S-ATA backplane receptacle. In certainembodiments, that backplane comprises a plurality of SAS backplanereceptacles such that each data storage device is interconnected withthe backplane by an SAS connector mated with an SAS backplanereceptacle.

In the illustrated embodiment of FIG. 2, backplane 200 comprises side290. A plurality of backplane receptacles is disposed on side 290 ofbackplane 200. The illustrated embodiment of FIG. 2 comprises backplanereceptacles 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260,265, 270, 275, and 280. In other embodiments, one or more backplanesdisposed in Applicants' information storage and retrieval system, suchas system 100, comprises fewer than 16 backplane receptacles. In stillother embodiments, one or more backplanes disposed in Applicants'information storage and retrieval system, such as system 100, comprisesmore than 16 backplane receptacles.

Each data storage device is interconnected to a connector which mateswith an a backplane receptacle. In certain embodiments each connectorcomprises a plurality of individual positions. In the illustratedembodiment of FIG. 3, connector 305 comprises 40 individual positions,namely positions 302, 304, 306, 308, 310, 312, 314, 316, 318, 320, 322,324, 326, 328, 330, 332, 334, 336,338, 340,342, 344, 346, 348, 350,352,354, 356, 358, 360, 362, 364, 366, 368, 370, 372, 374, 376, 378, and380. In the illustrated embodiment of FIG. 4, connector 405 comprises 80individual positions, namely positions 302 a/ 302 b, 304 a/ 304 b, 306a/ 306 b, 308 a/ 308 b, 310 a/ 310 b, 312 a/ 312 b, 314 a/ 314 b, 316 a/316 b, 318 a/ 318 b, 320 a/ 320 b, 322 a/ 322 b, 324 a/ 324 b, 326 a/326 b, 328 a/ 328 b, 330 a/ 330 b, 332 a/ 332 b, 334 a/ 334 b, 336 a/336 b, 338 a/ 338 b, 340 a/ 340 b, 342 a/ 342 b, 344 a/ 344 b, 346 a/346 b, 348 a/ 348 b, 350 a/ 350 b, 352 a/ 352 b, 354 a/ 354 b, 356 a/356 b, 358 a/ 358 b, 360 a/ 360 b, 362 a/ 362 b, 3642/364 b, 366 a/ 366b, 368 a/ 368 b, 370 a/ 370 b, 372 a/ 372 b, 374 a/ 374 b, 376 a/ 376 b,378 a/ 378 b, and 380 a/ 380 b.

In the illustrated embodiments of FIGS. 3 and 4, connectors 305 and 405comprises 40-position connectors. In other embodiments, each of theconnectors interconnected with a data storage device disposed inApplicants' information storage and retrieval system comprises an80-position connector.

In certain embodiments, a data storage device is interconnected by anSCA connector to an SCA backplane receptacle disposed Applicants'backplane 200. For example and referring to FIG. 5, which includes FIGS.5A and 5B, data storage device 505 is interconnected to SCA connector405 a. In the illustrated embodiment of FIG. 5 a plurality ofcommunication links 507 interconnect data storage device 505 and SCAconnector 405 a. SCA Connector 405 a mates with SCA receptacle 205.Similarly, data storage devices 510, 515, 520, 525, 530, 535, 540, 545,550, 555, 560,565, 570, 575, and 580, are interconnected to SCAconnectors 405 b, 405 c, 405 d, 405 e, 405 f, 405 g, 405 h, 405 i, 405j, 405 k, 405 l, 405 m, 405 n, and 405 p, respectively. In certainembodiments a plurality of communication links 512, 517, 522, 527, 532,537, 542, 547, 552, 557, 562, 567, 572, 577, and 482, interconnect datastorage devices 510, 515, 520, 525, 530, 535, 540, 545, 550, 555,560,565, 570, 575, and 580, respectively, and SCA connectors 405 b, 405c, 405 d, 405 e, 405 f, 405 g, 405 h, 405 i, 405 j, 405 k, 405 l, 405 m,405 n, and 405 p, respectively, which mate with SCA receptacles 210,215, 220, 225, 230, 235, 240, 245, 250, 255, 260,265, 270, 275, and 280,respectively.

In certain embodiments, each data storage device interconnected by anSCA connector to an SCA receptacle disposed on Applicants' backplanecomprises a “hot pluggable” device, wherein that data storage device canbe disconnected from the backplane while the remaining data storagedevices remain operational. For example in certain embodiments, datastorage device 505 can be disconnected from backplane 200 withoutinterrupting the operation of the other data storage devicesinterconnected with backplane 200. In certain embodiments, SCA connector405 a is releaseably connected with SCA receptacle 205 such thatconnector 405 a can be removed from SCA receptacle 205 withoutdisrupting the operation of data storage devices 510, 515, 520, 525,530, 535, 540, 545, 550, 555, 560,565, 570, 575, and 580.

The SFF-8045 Specification (the “Specification”) is directed to use of40-pin SCA-2 Connectors for use in applications for Fibre Channel diskdrives racked in a cabinet. The Specification is hereby incorporated byreference herein. The Specification requires that two LEDs be providedfor each data storage device disposed in the system, such as Applicants'information storage and retrieval system 100.

A first LED is denominated a FAULT LED, wherein that LED provides avisual indication in the event: (i) the drive is asserting both of theEnable Bypass signals, (ii) the drive has detected an internal failure,or (iii) the drive has been instructed by a host computer to turn on theFAULT LED. The Specification at Section 6.4.4 requires that such avisual indicated be colored yellow to indicate that it is a warningsignal.

A second LED is denominated a READY LED, wherein that LED provides avisual indication regarding the state of readiness and activity of thedrive. The Specification at Section 6.4.5 requires that such a visualindicator be colored white or green to indicate that normal activity isbeing performed. Optionally flashing patterns may be used to signalvendor unique conditions.

Using prior art apparatus and methods, a backplane having (N)interconnected data storage devices comprises (2N) LEDs, such that eachdata storage device is interconnected with one READY LED and one FAULTLED. Using such prior art apparatus and methods, the failure of any oneLED disposed on the backplane causes non-compliance with theSpecification. In order to remedy such non-compliance, the entirebackplane, and all interconnected data storage devices, may need to betaken out of service to replace the inoperative LED.

Using Applicants' apparatus and methods, a backplane having (N)interconnected data storage devices comprises (4N) LEDs, such that eachdata storage device is interconnected with two READY LEDs and two FAULTLEDs. Using Applicants' apparatus and method, the failure of any one LEDdisposed on the backplane does not cause non-compliance with theSpecification.

Because Applicants' backplane comprises two FAULT LEDs for each datastorage device interconnected to the backplane, that backplaneimplements an (N+1) redundancy for purposes of Section 6.4.4 ofSpecification. In such (N+1) redundancy embodiments, the failure of afirst FAULT LED interconnected with a data storage device does nottrigger a non-compliance event with the Specification because a secondFAULT LED interconnected with that data storage device remainsoperational.

Similarly, because Applicants' backplane comprises two READY LEDs foreach data storage device interconnected to the backplane, that backplaneimplements an (N+1) redundancy for purposes of Section 6.4.4 ofSpecification. In such (N+1) redundancy embodiments, the failure of afirst READY LED interconnected with a data storage device does nottrigger a non-compliance event with the Specification because a secondREADY LED interconnected with that data storage device remainsoperational.

Referring again to FIG. 5, LEDs 601, 602, 603, and 604, visuallyindicate the status of data storage device 505. LEDs 601 and 602 areeach capable of emitting first light comprising a first color. LEDs 603and 604 are each capable of emitting second light comprising a secondcolor, wherein the first color differs from the second color. In certainembodiments, the first color is yellow. In these embodiments, LEDs 601and 602 each comprise a FAULT LED for purposes of Section 6.4.4 of theSpecification. In the event LED 601 fails, LED 602 continues to providethe required visual indication under Section 6.4.4. In the event LED 602fails, LED 601 continues to provide the required visual indication underSection 6.4.4.

In certain embodiments, the second color is selected from the groupconsisting of white and green. In these embodiments, LEDs 603 and 604each comprise a READY LED for purposes of Section 6.4.5 theSpecification. In the event LED 603 fails, LED 604 continues to providethe required visual indication under Section 6.4.5. In the event LED 604fails, LED 603 continues to provide the required visual indication underSection 6.4.4.

Similarly, LEDS 606 and 607 are interconnected with data storage device510, LEDS 611 and 612 are interconnected with data storage device 515,LEDS 616 and 617 are interconnected with data storage device 520, LEDS621 and 622 are interconnected with data storage device 525, LEDS 626and 627 are interconnected with data storage device 530, LEDS 631 and632 are interconnected with data storage device 535, LEDS 636 and 637are interconnected with data storage device 540, LEDS 641 and 642 areinterconnected with data storage device 545, LEDS 646 and 647 areinterconnected with data storage device 550, LEDS 651 and 652 areinterconnected with data storage device 555, LEDS 656 and 657 areinterconnected with data storage device 560, LEDS 661 and 662 areinterconnected with data storage device 565, LEDS 666 and 667 areinterconnected with data storage device 570, LEDS 671 and 672 areinterconnected with data storage device 575, and LEDS 676 and 677 areinterconnected with data storage device 580, each comprise a firstcolor.

LEDS 608 and 609 are interconnected with data storage device 510, LEDS613 and 614 are interconnected with data storage device 515, LEDS 618and 619 are interconnected with data storage device 520, LEDS 623 and624 are interconnected with data storage device 525, LEDS 628 and 629are interconnected with data storage device 530, LEDS 633 and 634 areinterconnected with data storage device 535, LEDS 638 and 639 areinterconnected with data storage device 540, LEDS 643 and 644 areinterconnected with data storage device 545, LEDS 648 and 649 areinterconnected with data storage device 550, LEDS 653 and 654 areinterconnected with data storage device 555, LEDS 658 and 659 areinterconnected with data storage device 560, LEDS 663 and 664 areinterconnected with data storage device 565, LEDS 668 and 669 areinterconnected with data storage device 570, LEDS 673 and 674 areinterconnected with data storage device 575, and LEDS 678 and 679 areinterconnected with data storage device 580, each comprise a secondcolor, wherein the second color differs from the first color.

In certain embodiments, the first color is selected from the groupconsisting of yellow and green. In these embodiments, the second coloris selected from the group consisting of yellow and green, wherein thefirst color differs from the second color. In alternative embodiments,the first color is selected from the group consisting of yellow andwhite. In these alternative embodiments, the second color is selectedfrom the group consisting of yellow and white, wherein the first colordiffers from the second color.

Referring now to FIG. 8, in certain embodiments each data storagedevice, such as data storage device 505, comprises an LED driver foreach interconnected LED. In the illustrated embodiment of FIG. 8, datastorage device 505 comprises LED driver 810 and LED driver 830. Furtherin the illustrated embodiment of FIG. 8, the anode of LED 601 is tied toa system power plane 805 through current limiting resistor 820, and theanode of LED 602 is tied to the system power plane 805 through currentlimiting resistor 840.

If LEDs 601 and 602 emit yellow light, then if data storage device 505detects, inter alia, an internal failure, data storage device 505 pullsthe cathode of LED 601 towards ground using driver 810, causing currentto flow through resistor 820 and LED 601 thereby causing LED 601 to emityellow light, and data storage device 505 pulls the cathode of LED 602towards ground using driver 830, causing current to flow throughresistor 840 and LED 602 thereby causing LED 602 to emit yellow light.In the illustrated embodiment of FIG. 8, in the event one of the LEDs601 and 602 fails, then if data storage device 505 detects, inter alia,an internal failure, data storage device 505 pulls the cathode of theoperable LED towards ground using the LED driver interconnected with theoperable LED, causing current to flow through the resistorinterconnected with the operable LED thereby causing that operable LEDto emit yellow light.

If LEDs 601 and 602 emit white or green light, then if data storagedevice 505 remains operable, data storage device 505 pulls the cathodeof LED 601 towards ground using driver 810, causing current to flowthrough resistor 820 and LED 601 thereby causing LED 601 to emit eitherwhite or green light, and data storage device 505 pulls the cathode ofLED 602 towards ground using driver 830, causing current to flow throughresistor 840 and LED 602 thereby causing LED 602 to emit either white orgreen light. In the illustrated embodiment of FIG. 8, in the event oneof the LEDs 601 and 602 fails, and if data storage device remainsoperable, data storage device 505 pulls the cathode of the operable LEDtowards ground using the interconnected LED driver, causing current toflow through resistor interconnected with the operable LED therebycausing that operable LED to emit either white or green light.

Using the embodiment of FIG. 8, each data storage device interconnectedwith Applicants' backplane comprises four LED drivers, wherein each ofthose four LED drivers is interconnected with a different one of 4 LEDsdisposed on Applicants' backplane, and wherein each of those 4 LEDs isinterconnected with a system power plane via a current limitingresistor.

Referring now to FIG. 9, in certain embodiments each data storagedevice, such as data storage device 505, comprises an LED driver foreach pair of interconnected LEDs capable of emitting the same coloredlight. In the illustrated embodiment of FIG. 9, data storage device 505comprises LED driver 910. Further in the illustrated embodiment of FIG.9, the anode of LED 601 is tied to system power plane 805 throughcurrent limiting resistor 920, and the anode of LED 602 is tied tosystem power plane 805 through current limiting resistor 930.

In the illustrated embodiment of FIG. 9, if LEDs 601 and 602 emit yellowlight, then if data storage device 505 detects, inter alia, an internalfailure, data storage device 505 pulls the cathodes of LEDs 601 and 602towards ground using driver 910, causing current to flow throughresistors 920 and 930, and LEDs 601 and 602, thereby causing LEDs 601and 602 to emit yellow light. In the illustrated embodiment of FIG. 9,in the event one of the LEDs 601 and 602 fails, and if data storagedevice detects an internal failure, data storage device 505 pulls thecathode of the operable LED towards ground using the LED driverinterconnected to both the inoperable and the operable LED, causingcurrent to flow through the resistor interconnected with the operableLED thereby causing that operable LED to emit yellow light.

If LEDs 601 and 602 emit white or green light, then if data storagedevice 505 remains operable, data storage device 505 pulls the cathodesof LEDs 601 and 602 towards ground using driver 910, causing current toflow through resistors 920 and 930, and LEDs 601 and 602, therebycausing LEDs 601 and 602 to emit either white light or green light. Inthe illustrated embodiment of FIG. 9, in the event one of the LEDs 601and 602 fails, and if data storage device remains operable, data storagedevice 505 pulls the cathode of the operable LED towards ground usingthe LED driver interconnected to both the inoperable and the operableLED, causing current to flow through the resistor interconnected withthe operable LED thereby causing that operable LED to emit white orgreen light.

Using the embodiment of FIG. 9, each data storage device interconnectedwith Applicants' backplane comprises two LED drivers, wherein each ofthose two LED drivers is interconnected with a different pair of 2 LEDsdisposed on Applicants' backplane, and wherein each of those 4 LEDs isinterconnected with a system power plane via a current limitingresistor.

Referring now to FIG. 10, in certain embodiments each data storagedevice, such as data storage device 505, comprises an LED driver foreach pair of interconnected LEDs capable of emitting the same coloredlight. In the illustrated embodiment of FIG. 9, data storage device 505comprises LED driver 910. Further in the illustrated embodiment of FIG.8, the anodes of both LEDs 601 and LED 602 are tied to system powerplane 805 through current limiting resistor 1010.

In the illustrated embodiment of FIG. 10, if LEDs 601 and 602 emityellow light, then if data storage device 505 detects, inter alia, aninternal failure, data storage device 505 pulls the cathodes of LEDs 601and 602 towards ground using driver 910, causing current to flow throughresistor 1010, and LEDs 601 and 602, thereby causing LEDs 601 and 602 toeach emit a first quantum of yellow light. As those skilled in the artwill appreciate, the predominant failure mode for an LED comprises anopen circuit.

In the illustrated embodiment of FIG. 10, in the event one of the LEDs601 and 602 fails as an open circuit, and if data storage device detectsan internal failure, then data storage device 505 pulls the cathode ofthe operable LED towards ground using the LED driver interconnected toboth the inoperable and the operable LED, causing twice the normalamount of current to flow through the operable LED thereby causing thatoperable LED to emit a second quantum of yellow light, wherein thesecond quantum of yellow light is greater than the first quantum ofyellow light. As those skilled in the art will appreciate, the amount oflight emitted by a light emitting diode is proportional to the forwardcurrent. In the illustrated embodiment of FIG. 10, if one of a pair ofFAULT LEDs fails, then twice the amount of current flows through theoperable FAULT LED causing that operable FAULT LED to emit a greaterquantum of yellow light, i.e. the second quantum of yellow light.

If LEDs 601 and 602 emit white or green light, and if data storagedevice 505 remains operable, data storage device 505 pulls the cathodesof LEDs 601 and 602 towards ground using driver 910, causing current toflow through resistor 1010, and LEDs 601 and 602, thereby causing LEDs601 and 602 to emit a first quantum of either white light or greenlight. In the illustrated embodiment of FIG. 10, in the event one of theLEDs 601 and 602 fails, and if data storage device remains operable,data storage device 505 pulls the cathode of the operable LED towardsground using the LED driver interconnected to both the inoperable andthe operable LED, causing twice the normal amount of current to flowthrough the operable LED thereby causing that operable LED to emit asecond quantum of white or green light, wherein the second quantum oflight is greater than the first quantum of light.

Using the embodiment of FIG. 10, each data storage device interconnectedwith Applicants' backplane comprises two LED drivers, wherein each ofthose two LED drivers is interconnected with a different pair of 2 LEDsdisposed on Applicants' backplane, and wherein each pair of LEDs isinterconnected with a system power plane via one current limitingresistor.

In certain embodiments of Applicants' apparatus, a light pipe transmitsthe color emitted from each LED pair to a second location disposed inApplicants' information storage and retrieval system. By “light pipe,”Applicants mean an assembly comprising a plurality of optical fibers. Asthose skilled in the art will appreciate, optical fibres comprisestrands of transparent material which let light pass through the middle.The outer walls of such optical fibres act like a continual tube ofmirror, such that light travels along the fibre bouncing off themirror-like outer casing until it arrives at the other end of the fibre.In certain embodiments, Applicants' light pipes comprisepolymethylmethacrylate. In certain embodiments, Applicants' light pipescomprise polycarbonate.

Referring now to FIG. 6A, LED 601 comprises light emitting surface 697,and LED 602 comprises light emitting surface 698. In the illustratedembodiment of FIG. 6A, light pipe 701 comprises first end 702 and secondend 703. End 702 is disposed on light emitting surface 697 and lightemitting surface 698. The combined light emitted by LEDs 601 and 602 istransmitted through light pipe 701 and visually displayed at end 703.

Referring now to FIGS. 6B and 6C, light pipes 704, 707, 710, 713, 716,719, 722, 725, 728, 731, 734, 737, 740, 743, 746, 749, 752, 755, 758,761, 764, 767, 770, 773, 776, 779, 782, 785, 788, 791, and 794, comprisefirst ends 705, 708, 711, 714, 717, 720, 723, 726, 729, 732, 735, 738,741, 744, 747, 750, 753, 756, 759, 762, 765, 768, 771, 774, 777, 780,783, 786, 789, 792, and 795, respectively, wherein that first end isdisposed on light emitting surfaces of LEDs 603 and 604, 606 and 607,608 and 609, 611 and 612, 613 and 614, 616 and 617, 618 and 619, 621 and622, 623 and 624, 626 and 627, 628 and 629, 631 and 632, 633 and 634,636 and 637, 638 and 639, 641 and 642, 643 and 644, 646 and 647, 648 and649, 651 and 652, 653 and 654, 656 and 657, 658 and 659, 661 and 662,663 and 664, 666 and 667, 668 and 669, 671 and 672, 673 and 674, 676 and677, and 678 and 679, respectively, and wherein the light emitted bythose LEDs is transmitted to second ends 706, 709, 712, 715, 718, 721,724, 727, 730, 733, 736, 739, 742, 745, 748, 751, 754, 757, 760, 763,766, 769, 772, 775, 778, 781, 784, 787, 790, 793, and 796, respectively.

In certain embodiments of Applicants' information storage and retrievalsystem, a backplane, such as backplane 200, and the data storage devicesinterconnected with that backplane, are disposed within an enclosuredisposed in Applicants' system. For example and referring now to FIG. 7,enclosure 800 comprises exterior surface 810, and defines an enclosedspace 830. Backplane 200 and data storage devices 505, 510, 515, 520,525, 530, 535, 540, 545, 550, 555, 560, 565, 570, 575, and 580, aredisposed within enclosed space 830.

In the illustrated embodiment of FIG. 7, second ends 703, 706, 709, 712,715, 718, 721, 724, 727, 730, 733, 736, 739, 742, 745, 748, 751, 754,757, 760, 763, 766, 769, 772, 775, 778, 781, 784, 787, 790, 793, and796, of light pipes 701, 704, 707, 710, 713, 716, 719, 722, 725, 728,731, 734, 737, 740, 743, 746, 749, 752, 755, 758, 761, 764, 767, 770,773, 776, 779, 782, 785, 788, 791, and 794, respectively, are disposedon exterior surface 810, and visually display the light emitted by LEDs601 and 602, 603 and 604, 606 and 607, 608 and 609, 611 and 612, 613 and614, 616 and 617, 618 and 619, 621 and 622, 623 and 624, 626 and 627,628 and 629, 631 and 632, 633 and 634, 636 and 637, 638 and 639, 641 and642, 643 and 644, 646 and 647, 648 and 649, 651 and 652, 653 and 654,656 and 657, 658 and 659, 661 and 662, 663 and 664, 666 and 667, 668 and669, 671 and 672, 673 and 674, 676 and 677, and 678 and 679,respectively.

In embodiments, wherein LEDs 601 and 602 emit a yellow color, and in theevent data storage device 505 detects an internal failure, then datastorage device 505 causes LEDs 601 and 602 to emit yellow light, andthose combined yellow-colored emissions are transmitted by light pipe701 to second end 703 disposed on exterior surface 810 of enclosure 800wherein those combined yellow-colored emissions are visually displayed.Similarly, the light emitted by any of the above-described LED pairs istransmitted by the interconnected light pipe to the second end of thatlight pipe disposed on surface 810 and visually displayed.

In certain embodiments, a lens assembly is disposed on the second end ofeach light pipe disposed on surface 810. Referring now to FIG. 11,second end 703 of light pipe 701 is received into bayonet assembly 1110and secured in such assembly by an adhesive. Bayonet assembly 1110 isinserted into receiver assembly 1120, which holds a lens 1130. Incertain embodiments, lens 1130 comprises a plano-convex lens, anaspherical lens, a holographic lens, a Fresnel lens or a flat lens, madefrom either glass or plastic. In certain embodiments, receiver assembly1120 comprises Acrylonitrile Butadiene Styrene (ABS). In certainembodiments, receiver assembly 1120 is “platable” in that it can acceptsuch coatings as chrome or brass, for reflective purposes.

Applicants' invention comprises a method to visually indicate the statusof a data storage device. Referring now to FIG. 12, in step 1210Applicants' method provides a data storage device, such as data storagedevice 505, comprising one or more LED drivers, such as LED drivers 810(FIG. 8) and 830 (FIG. 8), where that data storage device isinterconnected to a backplane, such as backplane 200, disposed inApplicants' information storage and retrieval system, such as system100. In certain embodiments, Applicants' backplane comprises one or moreSCA receptacles, and Applicants' data storage device is interconnectedwith an SCA connector, wherein that SCA connector can be releaseablyattached to an SCA receptacle disposed on the backplane.

In step 1215, Applicants' method disposes a first LED, such as LED 601,on the backplane, where that first LED comprises a first light emittingsurface, such as light emitting surface 697. In step 1220, Applicants'method disposes a second LED, such as LED 602, on the backplane, wherethat second LED comprises a second light emitting surface, such as lightemitting surface 698.

In step 1225, Applicants' method determines if the data storage deviceprovided in step 1210 comprises an LED driver for each interconnectedLED. If Applicants' method determines in step 1225 that the data storagedevice does not comprise an LED driver for each interconnected LED, thenthe method transitions from step 1225 to step 1240 wherein the methodinterconnects the cathodes of both the first LED and the second LED toan LED driver disposed in the data storage device.

Applicants' method transitions from step 1240 to step 1245 wherein themethod determines if a separate current limiting resistor will be usedfor each LED interconnected with the data storage device. If Applicants'method determines in step 1245 that a separate current limiting resistorwill not be used for each interconnected LED, then the methodtransitions from step 1245 to step 1260 wherein the method provides acurrent limiting resistor and interconnects that current limitingresistor interconnected with a power plane disposed in Applicants'information storage and retrieval system and with the anodes of both thefirst LED and the second LED. Applicants' method transitions from step1260 to step 1265.

If Applicants' method determines in step 1245 that a separate currentlimiting resistor will be used for each LED interconnected with the datastorage device, then the method transitions from step 1245 to step 1250wherein the method provides a first current limiting resistor andinterconnects that first current limiting resistor to a power planedisposed in Applicants' information storage and retrieval system, and tothe anode of the first LED.

Applicants' method transitions from step 1250 to step 1255 wherein themethod provides a second current limiting resistor and interconnectsthat second current limiting resistor to a power plane disposed inApplicants' information storage and retrieval system, and to the anodeof the second LED. In certain embodiments, the first current limitingresistor and the second current limiting resistor comprise substantiallythe same resistance. Applicants' method transitions from step 1255 tostep 1265.

If Applicants' method determines in step 1225 that the data storagedevice comprises a different LED driver for each interconnected LED,then the method transitions from step 1225 to step 1230 wherein themethod interconnects the cathode of the first LED to a first LED driver.Applicants' method transitions from step 1230 to step 1235 wherein themethod interconnects the cathode of the second LED to a second LEDdriver. Applicants' method transitions from step 1235 to step 1250 andcontinues as described herein.

In step 1265, Applicants' method determines if a light pipe is used totransmit light from said first LED and said second LED to a differentlocation in Applicants' information storage and retrieval system. IfApplicants' method determines that a light pipe is used, then the methodtransitions from step 1265 to step 1270 wherein the method provides alight pipe having a first end and a second end, and disposes the firstend of that light pipe on a light emitting surface of the first LED, andon a light emitting surface of the second LED. In certain embodiments,Applicants' method transitions from step 1270 to step 1280. In otherembodiments, Applicants' method transitions from step 1270 to step 1275wherein the method provides a lens assembly, such as the lens assembly1100 (FIG. 11), and attaches that lens assembly on the second end of thelight pipe of step 1270. Applicants' method transitions from step 1275to step 1280 wherein the method determines if the first LED and thesecond LED are capable of emitting yellow light. If Applicants' methoddetermines in step 1280 that the first LED and the second LED arecapable of emitting yellow light, then the method transitions from step1280 to step 1310. Alternatively, if Applicants' method determines instep 1280 that the first LED and the second LED are not capable ofemitting yellow light, then the method transitions from step 1280 tostep 1410.

Referring now to FIG. 13, in step 1310 Applicants' data storage devicedetects an internal failure. Applicants' method transitions from step1310 to step 1320 wherein Applicants' data storage device pulls thecathode of the first LED to ground. Applicants' method transitions fromstep 1320 to step 1330 wherein the first LED emits yellow light.

Applicants' method transitions from step 1330 to step 1340 whereinApplicants' data storage device pulls the cathode of the second LED toground. Applicants' method transitions from step 1340 to step 1350wherein the second LED emits yellow light.

Applicants' method transitions from step 1350 to step 1360 wherein themethod determines if one of the two LEDs failed. If either the firstLED, or the second LED, fails, then Applicants' method transitions fromstep 1360 to step 1370 wherein the operable LED emits yellow light.Alternatively, if neither the first LED, nor the second LED, fails, thenApplicants' method transitions from step 1360 to step 1380 wherein bothLEDs emit yellow light.

Referring now to FIG. 14, in step 1410 Applicants' data storage deviceremains operative. Applicants' method transitions from step 1410 to step1420 wherein Applicants' data storage device pulls the cathode of thefirst LED to ground. Applicants' method transitions from step 1420 tostep 1430 wherein the first LED emits either white or green light.

Applicants' method transitions from step 1430 to step 1440 whereinApplicants' data storage device pulls the cathode of the second LED toground. Applicants' method transitions from step 1440 to step 1450wherein the second LED emits either white or green light.

Applicants' method transitions from step 1450 to step 1460 wherein themethod determines if one of the two LEDs failed. If either the firstLED, or the second LED, fails, then Applicants' method transitions fromstep 1460 to step 1470 wherein the operable LED emits either white orgreen light. Alternatively, if neither the first LED, nor the secondLED, fails, then Applicants' method transitions from step 1460 to step1480 wherein both LEDs emit either white or green light.

An information storage and retrieval system which utilizes Applicants'apparatus and method comprises an enhanced mean time between failure(“MTBF”) in comparison to an information storage and retrieval systemusing prior art apparatus and methods. A storage services providerutilizing an information storage and retrieval system which comprisessuch an enhanced MTBF achieved by implementing, inter alia, Applicants'method recited in FIGS. 12, 13, and/or 14, is able to providecost-effective information storage services to one or more storageservices customers.

The embodiments of Applicants' method recited in FIGS. 12, 13, and/or14, may be implemented separately. Moreover, in certain embodiments,individual steps recited in FIGS. 12, 13, and/or 14, may be combined,eliminated, or reordered.

While the preferred embodiments of the present invention have beenillustrated in detail, it should be apparent that modifications andadaptations to those embodiments may occur to one skilled in the artwithout departing from the scope of the present invention as set forthin the following claims.

1. A data storage and retrieval system, comprising: a data storagedevice; a first LED interconnected with said data storage device,wherein said first LED is capable of emitting first light comprising afirst color; a second LED interconnected with said data storage device,wherein said second LED is capable of emitting said first light; a thirdLED interconnected with said data storage device, wherein said third LEDis capable of emitting second light comprising a second color; a fourthLED interconnected with said data storage device, wherein said fourthLED is capable of emitting said second light; wherein said data storagedevice causes said first LED and said second LED to emit said firstlight if said data storage device detects an internal failure; andwherein said storage device causes said third LED and said fourth LED toemit said second light if said data storage device is operative.
 2. Thedata storage and retrieval system of claim 1, further comprising: abackplane interconnected with said data storage device; wherein saidfirst LED, said second LED, said third LED, and said fourth LED, aredisposed on said backplane.
 3. The information storage and retrievalsystem of claim 1, wherein: said first LED further comprises a firstlight emitting surface; said second LED further comprises a second lightemitting surface; said third LED further comprises a third lightemitting surface; said fourth LED further comprises a fourth lightemitting surface; further comprising: a first light pipe having a firstend and a second end, wherein said first end of said first light pipe isdisposed on said first light emitting surface and on said second lightemitting surface; and a second light pipe having a first end and asecond end, wherein said first end of said second light pipe is disposedon said third light emitting surface and on said fourth light emittingsurface.
 4. The information storage and retrieval system of claim 3,further comprising an enclosure comprising an exterior surface, whereinsaid data storage device and said backplane are disposed in saidenclosure, and wherein said second end of said first light pipe isdisposed on said exterior surface, and wherein said second end of saidsecond light pipe is disposed on said exterior surface.
 5. Theinformation storage and retrieval system of claim 4, further comprising:a first lens assembly disposed on said second end of said first lightpipe; and a second lens assembly disposed on said second end of saidsecond light pipe.
 6. The information storage and retrieval system ofclaim 2, further comprising: a connector selected from the groupconsisting of an SCA connector, an S-ATA connector, and a SAS connector,interconnected with said data storage device; a receptacle, selectedfrom the group consisting of an SCA receptacle, an S-ATA receptacle, anda SAS receptacle, disposed on said backplane; wherein said connector canbe releaseably connected to said receptacle.
 7. The information storageand retrieval system of claim 6, wherein said connector comprises a 40position SCA connector.
 8. The information storage and retrieval systemof claim 6, wherein said connector comprises an 80 position SCAconnector.
 9. The information storage and retrieval system of claim 6,further comprising one or more additional information storage devicesreleaseably attached to said backplane, wherein said data storage devicecan be disconnected from said backplane without disrupting the operationof said additional information storage devices.
 10. The informationstorage and retrieval system of claim 1, wherein: said first LED furthercomprises a first cathode and a first anode; said second LED furthercomprises a second cathode and a second anode; said third LED furthercomprises a third cathode and a third anode; said fourth LED furthercomprises a fourth cathode and a fourth anode; further comprising: asystem power plane; a first LED driver disposed in said data storagedevice, wherein said first LED driver is interconnected with said firstcathode; a first current limiting resistor interconnected with saidpower plane and said first anode; a second LED driver disposed in saiddata storage device, wherein said second LED driver is interconnectedwith said second cathode; a second current limiting resistorinterconnected with said power plane and said second anode; a third LEDdriver disposed in said data storage device, wherein said third LEDdriver is interconnected with said third cathode; a third currentlimiting resistor interconnected with said power plane and said thirdanode; and a fourth LED driver disposed in said data storage device,wherein said fourth LED driver is interconnected with said fourthcathode; a fourth current limiting resistor interconnected with saidpower plane and said fourth anode.
 11. The information storage andretrieval system of claim 1, wherein: said first LED further comprises afirst cathode and a first anode; said second LED further comprises asecond cathode and a second anode; said third LED further comprises athird cathode and a third anode; said fourth LED further comprises afourth cathode and a fourth anode; further comprising: a system powerplane; a first LED driver disposed in said data storage device, whereinsaid first LED driver is interconnected with said first cathode and withsaid second cathode; a first current limiting resistor interconnectedwith said power plane and said first anode; a second current limitingresistor interconnected with said power plane and said second anode; asecond LED driver disposed in said data storage device, wherein saidsecond LED driver is interconnected with said third cathode and withsaid fourth cathode; a third current limiting resistor interconnectedwith said power plane and said third anode; and a fourth currentlimiting resistor interconnected with said power plane and said fourthanode.
 12. The information storage and retrieval system of claim 1,wherein: said first LED further comprises a first cathode and a firstanode; said second LED further comprises a second cathode and a secondanode; said third LED further comprises a third cathode and a thirdanode; said fourth LED further comprises a fourth cathode and a fourthanode; further comprising: a system power plane; a first LED driverdisposed in said data storage device, wherein said first LED driver isinterconnected with said first cathode and with said second cathode; afirst current limiting resistor interconnected with said power plane andwith both said first anode and said second anode; a second LED driverdisposed in said data storage device, wherein said second LED driver isinterconnected with said third cathode and with said fourth cathode; asecond current limiting resistor interconnected with said power planeand with both said third anode and said fourth anode.
 13. A method tovisually display the status of a data storage device, comprising thesteps of: providing a data storage device; providing a first LED capableof emitting first tight comprising a first color; providing a second LEDcapable of emitting said first light; interconnecting said first LED andsaid second LED with said data storage device; emitting first light fromsaid first LED and from said second LED to indicate whether said datastorage device is operational; said first LED further comprises a firstlight emitting surface, and said second LED further comprises a secondlight emitting surface; said method further comprising the step of:providing a light pipe comprising a first end and a second end;disposing said first end of said light pipe on said first light emittingsurface and on said second light emitting surface; transmitting saidfirst light from said first LED and from said second LED to said secondend of said light pipe.
 14. The method of claim 13, further comprisingthe steps of: providing a lens assembly; disposing said lens assembly onsaid second end of said light pipe; and displaying said first tight fromsaid lens assembly.
 15. The method of claim 14, further comprising thesteps of: providing an enclosure comprising an exterior surface;disposing said data storage device and said backplane in said enclosure;disposing said lens assembly on said exterior surface.
 16. A method toprovide information storage services, comprising the steps of: providingdata storage services to one or more storage services customers using aninformation storage and retrieval system comprising: a data storagedevice; a first LED interconnected with said data storage device,wherein said first LED is capable of emitting first light comprising afirst color; a second LED interconnected with said data storage device,wherein said second LED is capable of emitting said first light; a thirdLED interconnected with said data storage device, wherein said third LEDis capable of emitting second light comprising a second color; a fourthLED interconnected with said data storage device, wherein said fourthLED is capable of emitting said second light; wherein said data storagedevice causes said first LED and said second LED to emit said firstlight if said data storage device detects an internal failure; andwherein said storage device causes said third LED and said fourth LED toemit said second light if said data storage device is operative.
 17. Themethod of claim 16, wherein said information storage and retrievalsystem further comprises: a backplane interconnected with said datastorage device; wherein said first LED, said second LED, said third LED,and said fourth LED, are disposed on said backplane.
 18. The method ofclaim 16, wherein: said first LED further comprises a first Lightemitting surface; said second LED further comprises a second lightemitting surface; said third LED further comprises a third lightemitting surface; said fourth LED further comprises a fourth lightemitting surface; wherein said information storage and retrieval systemfurther comprises: a first light pipe having a first end and a secondend, wherein said first end of said first light pipe is disposed on saidfirst light emitting surface and on said second light emitting surface;and a second light pipe having a first end and a second end, whereinsaid first end of said second light pipe is disposed on said third lightemitting surface and on said fourth light emitting surface.
 19. Themethod of claim 16, wherein said information storage and retrievalsystem further comprises an enclosure comprising an exterior surface,wherein said data storage device and said backplane are disposed in saidenclosure, and wherein said second end of said first light pipe isdisposed on said exterior surface, and wherein said second end of saidsecond light pipe is disposed on said exterior surface.
 20. The methodof claim 16, wherein said information storage and retrieval systemfurther comprises: a first lens assembly disposed on said second end ofsaid first light pipe; and a second lens assembly disposed on saidsecond end of said second light pipe.